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How the CVE Works
CVE-2025-48799 is a privilege escalation vulnerability in Windows Update Service caused by improper link resolution (“link following”). An attacker with local access can exploit symbolic links or junctions to redirect file operations to unintended locations, bypassing security checks. By manipulating the update service’s file access routines, the attacker gains elevated SYSTEM privileges. The flaw stems from insufficient validation of path traversal during update installations, allowing maliciously crafted paths to execute arbitrary code with higher permissions.
DailyCVE Form
Platform: Windows Update Service
Version: Pre-July 2025 patches
Vulnerability: Privilege Escalation
Severity: Critical
Date: 07/15/2025
Prediction: Patch expected by 08/05/2025
What Undercode Say
Check symbolic link handling fsutil behavior query SymlinkEvaluation Monitor file access Procmon - Filter "Path contains WindowsUpdate"
How Exploit
1. Create malicious junction pointing to system directories.
- Trigger update service to write/execute via crafted path.
3. Escalate to SYSTEM via DLL hijacking.
Protection from this CVE
- Apply Microsoft’s patch.
- Restrict symbolic link creation.
- Audit service file permissions.
Impact
- Full system compromise.
- Bypass of user privilege separation.
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
